Back to Freecodecamp

JavaScript Functions Quiz

curriculum/challenges/english/blocks/quiz-javascript-functions/66edcc779993c0da6906dbb9.md

latest7.2 KB
Original Source

--description--

To pass the quiz, you must correctly answer at least 18 of the 20 questions below.

--quizzes--

--quiz--

--question--

--text--

Which of the following is the correct way to declare a function in JavaScript?

--distractors--

js
func greet() {
  console.log("Hello there!");
}

js
defineFunction greet() {
  console.log("Hello there!");
}

js
def greet() {
  console.log("Hello there!");
}

--answer--

js
function greet() {
  console.log("Hello there!");
}

--question--

--text--

What happens when you call (or execute) a function?

--distractors--

The code inside the function will run and null will always be returned.


Nothing will happen when you call a function.


A TypeError will be thrown and the program will crash.

--answer--

The code inside the function will run and a value will be returned.

--question--

--text--

Which of the following is the correct way to call a function?

--distractors--

js
exampleFunction;

js
exampleFunction>>;

js
()exampleFunction();

--answer--

js
exampleFunction();

--question--

--text--

What is the role of the return keyword?

--distractors--

The return keyword will execute the function.


The return keyword will throw a type error.


The return keyword serves no purpose in functions.

--answer--

The return keyword returns a value from the function.

--question--

--text--

Which of the following is a valid function expression?

--distractors--

js
expression function getSum(x, y) {
    return x + y;
};

js
getSum: function(x, y) {
    return x + y;
};

js
function = getSum(x, y) {
    return x + y;
};

--answer--

js
const getSum = function(x, y) {
    return x + y;
};

--question--

--text--

What are function arguments?

--distractors--

Values that represents the absence of a value.


Special values that act similar to anonymous functions.


Placeholder values used inside of the function.

--answer--

Real values passed to a function when it is called.

--question--

--text--

What are function parameters?

--distractors--

Floating point values used inside of the function.


Values passed to a function when it is called.


Values that represent the intentional absence of the value.

--answer--

Values listed inside the function definition.

--question--

--text--

What will be logged to the console?

js
const calculateTotal = (amount, taxRate = 0.05) => {
  return amount + (amount * taxRate);
};

console.log(calculateTotal(100));

--distractors--

10


undefined


1

--answer--

105

--question--

--text--

Which of the following is the correct syntax for an arrow function?

--distractors--

js
const sum <<>> (num1, num2) => num1 + num2

js
const sum === (num1, num2) === num1 + num2

js
const sum >=> (num1, num2) => num1 + num2

--answer--

js
const sum = (num1, num2) => num1 + num2

--question--

--text--

What will be result for the following code?

js
function greet() {
  const developer = "Jessica";
  console.log("Hello there!");
}

console.log(developer);

--distractors--

Nothing will happen and the code will run normally.


The string "Hello there!" will be logged to the console.


The string "Hello!" will be logged to the console.

--answer--

You will get a reference error because developer is not defined globally.

--question--

--text--

When can you omit a set of parentheses around a parameter list for an arrow function?

--distractors--

You should always omit the parentheses around a parameter list.


You are never supposed to omit the parentheses for an arrow function.


You should only omit the parentheses when you are working with multiple parameters.

--answer--

You should only omit the parentheses when you only have one parameter.

--question--

--text--

When can you omit the curly braces and return keyword for an arrow function?

--distractors--

You should always omit the curly braces and return keyword.


You should never omit the curly braces and return keyword.


When the function body has multiple lines of code.

--answer--

When the function body consists of a single expression.

--question--

--text--

What will the following function return?

js
function exampleFunction() {
  return "Hello";
  return "World!";
};

--distractors--

"World!"


"Hello World!"


undefined

--answer--

"Hello"

--question--

--text--

Which of the following is the correct way to use default parameters?

--distractors--

js
function sum(num1, num2 <<>> 12) {
  return num1 + num2
}

js
function sum(num1, num2 === 12) {
  return num1 + num2
}

js
function sum(num1, num2 >> 12) {
  return num1 + num2
}

--answer--

js
function sum(num1, num2 = 12) {
  return num1 + num2
}

--question--

--text--

What will be the result for the following code?

js
const developer = "Jessica";

function greet() {
  console.log("Hello, " + developer)
}

greet();

--distractors--

The string "Hello, developer" will be logged to the console.


An error message will display in the console.


Nothing will display in the console.

--answer--

The string "Hello, Jessica" will be logged to the console.

--question--

--text--

What happens if you try to remove the curly braces for a regular function?

--distractors--

An alert box will display on the page with an error.


The program will crash and not start again.


Nothing will happen.

--answer--

You will get a syntax error.

--question--

--text--

What will be the result for the following code?

js
const sum = (num1, num2) => num1 + num2
console.log(sum(0, 0) + 10);

--distractors--

An error message will display in the console.


The number 0 will be logged to the console.


Nothing will be logged to the console.

--answer--

The number 10 will be logged to the console.

--question--

--text--

What will be the output for the following code?

js
const exampleFunction = (param1, param2) => param1 + param2;
console.log(exampleFunction(3, "Something"));

--distractors--

null


undefined


3 + "Something"

--answer--

"3Something"

--question--

--text--

What will be the result for the following code?

js
const sum = (num1, num2) => num1 + num2
console.log(sum(0, 0) + num2);

--distractors--

An error message saying num1 is not defined.


The number 0 will be displayed in the console.


undefined will be displayed in the console.

--answer--

An error message saying num2 is not defined.

--question--

--text--

What will be the output for the following code?

js
const divideTwoNumbers = (num1, num2) => num1 / num2;
console.log(divideTwoNumbers(3, 0));

--distractors--

Error


0


null

--answer--

Infinity